class Counter2{
    private int count=0;

    public void add(){
        synchronized (this){
            count++;
        }
    }

    public int get(){
        return count;
    }
}
public class ThreadDemo19MuchS {
    public static void main(String[] args) throws InterruptedException {
        Counter2 counter2=new Counter2();
        Thread t1=new Thread(()->{
           synchronized (counter2){
               synchronized (counter2){
                   synchronized (counter2){
                       counter2.add();
                   }
               }
           }
        });
        t1.start();
        t1.join();
        System.out.println("count="+counter2.get());
    }
}
